Heat-killed Lactiplantibacillus plantarum WB3813 and Lactiplantibacillus plantarum WB3814 Alleviate LPS-Induced Inflammatory Damage and Apoptosis in A549 Cells.

Chronic obstructive pulmonary disease (COPD) is characterized by chronic lung inflammation and apoptosis. Although paraprobiotics are known for their beneficial effects on respiratory health, research on their effect on COPD is limited. In this study, we investigated the effects of heat-killed Lactiplantibacillus plantarum WB3813 and Lact. plantarum WB3814 on inflammation and apoptosis in lipopolysaccharide (LPS)-induced A549 cells. Both strains demonstrated appropriate probiotic properties and were confirmed to be safe. The results showed that heat-killed lactic acid bacteria (H-LAB) exhibited anti-inflammatory and anti-apoptotic effects. Although LPS exposure reduced cell viability, treatment with the two H-LAB demonstrated a protective effect on the cells. RT-PCR results showed that H-LAB pretreatment reduced COPD-related mRNA expression levels, and western blotting analysis indicated downregulation of the activation NF-κB and intrinsic apoptotic signaling pathways. Additionally, elevated levels of IL-6 and eotaxin induced by LPS decreased. Furthermore, the strains significantly lowered intracellular ROS levels, which were increased by LPS, and promoted radical-scavenging activity. Although the in vivo effects have not yet been elucidated, this study demonstrated that heat-killed or live Lact. plantarum WB3813 and Lact. plantarum WB3814 exhibit anti-inflammatory and anti-apoptotic effects in a lung epithelial cell injury model. These findings provide experimental evidence for the development of functional foods to improve bronchial health and for potential clinical applications in COPD treatment.